NMaximize is not converging to a solution
$begingroup$
I am trying to use NMaximize
to find the maximum value of a variable that satisfies the given constraints. Since the constraints aren't straightforward, I am using the function.
I can see the constraints are such that the value is bounded but I get the below warning messages:
NMaximize::cvmit: Failed to converge to the requested accuracy or
precision within 100000 iterations.
NMaximize::cvdiv: Failed to
converge to a solution. The function may be unbounded.
The constraint and the way I am using the function is as below:
constraint = (x | y) [Element]
Integers && ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x -
3.63201*10^84 x^2]) || (10713. <= x <= 19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x - 3.63201*10^84 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x - 3.63201*10^84 x^2]))
maxX =
NMaximize[{x, constraint}, {x, y}, MaxIterations -> 100000]
I have increased the MaxIterations
from 100 to 100000 but it doesn't seem to converge. I am not sure if increasing the MaxIterations
is the solution. Can you please guide me with this?
functions maximum
$endgroup$
|
show 1 more comment
$begingroup$
I am trying to use NMaximize
to find the maximum value of a variable that satisfies the given constraints. Since the constraints aren't straightforward, I am using the function.
I can see the constraints are such that the value is bounded but I get the below warning messages:
NMaximize::cvmit: Failed to converge to the requested accuracy or
precision within 100000 iterations.
NMaximize::cvdiv: Failed to
converge to a solution. The function may be unbounded.
The constraint and the way I am using the function is as below:
constraint = (x | y) [Element]
Integers && ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x -
3.63201*10^84 x^2]) || (10713. <= x <= 19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x - 3.63201*10^84 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x - 3.63201*10^84 x^2]))
maxX =
NMaximize[{x, constraint}, {x, y}, MaxIterations -> 100000]
I have increased the MaxIterations
from 100 to 100000 but it doesn't seem to converge. I am not sure if increasing the MaxIterations
is the solution. Can you please guide me with this?
functions maximum
$endgroup$
$begingroup$
Could try maximizing over individual regions of the piecewise set-up. But the machine precision values will make validation of inequalities kind of iffy.
$endgroup$
– Daniel Lichtblau
11 hours ago
1
$begingroup$
I'm not seeing what $y$ has to do with this. Wouldn't the maximum value of $x$ be 19762?constraint /. x -> 19762
results iny [Element] Integers && 7229.16 < y < 7344.29
andconstraint /. x -> 19763
results inFalse
.
$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB, I think forx
,y
isn't needed. Thanks for pointing this out. But if I am trying to maximizey
, I need to maximize over both the variables sincey
is an expression ofx
, right?
$endgroup$
– gaganso
11 hours ago
$begingroup$
Yes, if that's what you want. The general solution appears to be $x = 19762$ and $7230leq y leq 7344$. So to maximize $y$ you'd choose $7344$.
$endgroup$
– JimB
10 hours ago
1
$begingroup$
OK. I was assuming that you were conditioning on the maximum value of $x$.
$endgroup$
– JimB
10 hours ago
|
show 1 more comment
$begingroup$
I am trying to use NMaximize
to find the maximum value of a variable that satisfies the given constraints. Since the constraints aren't straightforward, I am using the function.
I can see the constraints are such that the value is bounded but I get the below warning messages:
NMaximize::cvmit: Failed to converge to the requested accuracy or
precision within 100000 iterations.
NMaximize::cvdiv: Failed to
converge to a solution. The function may be unbounded.
The constraint and the way I am using the function is as below:
constraint = (x | y) [Element]
Integers && ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x -
3.63201*10^84 x^2]) || (10713. <= x <= 19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x - 3.63201*10^84 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x - 3.63201*10^84 x^2]))
maxX =
NMaximize[{x, constraint}, {x, y}, MaxIterations -> 100000]
I have increased the MaxIterations
from 100 to 100000 but it doesn't seem to converge. I am not sure if increasing the MaxIterations
is the solution. Can you please guide me with this?
functions maximum
$endgroup$
I am trying to use NMaximize
to find the maximum value of a variable that satisfies the given constraints. Since the constraints aren't straightforward, I am using the function.
I can see the constraints are such that the value is bounded but I get the below warning messages:
NMaximize::cvmit: Failed to converge to the requested accuracy or
precision within 100000 iterations.
NMaximize::cvdiv: Failed to
converge to a solution. The function may be unbounded.
The constraint and the way I am using the function is as below:
constraint = (x | y) [Element]
Integers && ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x -
3.63201*10^84 x^2]) || (10713. <= x <= 19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x - 3.63201*10^84 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-43 Sqrt[
4.98614*10^92 + 4.65469*10^88 x - 3.63201*10^84 x^2]))
maxX =
NMaximize[{x, constraint}, {x, y}, MaxIterations -> 100000]
I have increased the MaxIterations
from 100 to 100000 but it doesn't seem to converge. I am not sure if increasing the MaxIterations
is the solution. Can you please guide me with this?
functions maximum
functions maximum
asked 12 hours ago
gagansogaganso
1528
1528
$begingroup$
Could try maximizing over individual regions of the piecewise set-up. But the machine precision values will make validation of inequalities kind of iffy.
$endgroup$
– Daniel Lichtblau
11 hours ago
1
$begingroup$
I'm not seeing what $y$ has to do with this. Wouldn't the maximum value of $x$ be 19762?constraint /. x -> 19762
results iny [Element] Integers && 7229.16 < y < 7344.29
andconstraint /. x -> 19763
results inFalse
.
$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB, I think forx
,y
isn't needed. Thanks for pointing this out. But if I am trying to maximizey
, I need to maximize over both the variables sincey
is an expression ofx
, right?
$endgroup$
– gaganso
11 hours ago
$begingroup$
Yes, if that's what you want. The general solution appears to be $x = 19762$ and $7230leq y leq 7344$. So to maximize $y$ you'd choose $7344$.
$endgroup$
– JimB
10 hours ago
1
$begingroup$
OK. I was assuming that you were conditioning on the maximum value of $x$.
$endgroup$
– JimB
10 hours ago
|
show 1 more comment
$begingroup$
Could try maximizing over individual regions of the piecewise set-up. But the machine precision values will make validation of inequalities kind of iffy.
$endgroup$
– Daniel Lichtblau
11 hours ago
1
$begingroup$
I'm not seeing what $y$ has to do with this. Wouldn't the maximum value of $x$ be 19762?constraint /. x -> 19762
results iny [Element] Integers && 7229.16 < y < 7344.29
andconstraint /. x -> 19763
results inFalse
.
$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB, I think forx
,y
isn't needed. Thanks for pointing this out. But if I am trying to maximizey
, I need to maximize over both the variables sincey
is an expression ofx
, right?
$endgroup$
– gaganso
11 hours ago
$begingroup$
Yes, if that's what you want. The general solution appears to be $x = 19762$ and $7230leq y leq 7344$. So to maximize $y$ you'd choose $7344$.
$endgroup$
– JimB
10 hours ago
1
$begingroup$
OK. I was assuming that you were conditioning on the maximum value of $x$.
$endgroup$
– JimB
10 hours ago
$begingroup$
Could try maximizing over individual regions of the piecewise set-up. But the machine precision values will make validation of inequalities kind of iffy.
$endgroup$
– Daniel Lichtblau
11 hours ago
$begingroup$
Could try maximizing over individual regions of the piecewise set-up. But the machine precision values will make validation of inequalities kind of iffy.
$endgroup$
– Daniel Lichtblau
11 hours ago
1
1
$begingroup$
I'm not seeing what $y$ has to do with this. Wouldn't the maximum value of $x$ be 19762?
constraint /. x -> 19762
results in y [Element] Integers && 7229.16 < y < 7344.29
and constraint /. x -> 19763
results in False
.$endgroup$
– JimB
11 hours ago
$begingroup$
I'm not seeing what $y$ has to do with this. Wouldn't the maximum value of $x$ be 19762?
constraint /. x -> 19762
results in y [Element] Integers && 7229.16 < y < 7344.29
and constraint /. x -> 19763
results in False
.$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB, I think for
x
, y
isn't needed. Thanks for pointing this out. But if I am trying to maximize y
, I need to maximize over both the variables since y
is an expression of x
, right?$endgroup$
– gaganso
11 hours ago
$begingroup$
@JimB, I think for
x
, y
isn't needed. Thanks for pointing this out. But if I am trying to maximize y
, I need to maximize over both the variables since y
is an expression of x
, right?$endgroup$
– gaganso
11 hours ago
$begingroup$
Yes, if that's what you want. The general solution appears to be $x = 19762$ and $7230leq y leq 7344$. So to maximize $y$ you'd choose $7344$.
$endgroup$
– JimB
10 hours ago
$begingroup$
Yes, if that's what you want. The general solution appears to be $x = 19762$ and $7230leq y leq 7344$. So to maximize $y$ you'd choose $7344$.
$endgroup$
– JimB
10 hours ago
1
1
$begingroup$
OK. I was assuming that you were conditioning on the maximum value of $x$.
$endgroup$
– JimB
10 hours ago
$begingroup$
OK. I was assuming that you were conditioning on the maximum value of $x$.
$endgroup$
– JimB
10 hours ago
|
show 1 more comment
2 Answers
2
active
oldest
votes
$begingroup$
Rationalize
the constraint:
constraint2 = ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y < 2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2]) || (10713. <= x <=
19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-1 Sqrt[4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2])) //
Rationalize[#, 0] & // Simplify;
With the Rationalized
constraint you can use Maximize
:
maxX = Maximize[{x, constraint2}, {x, y}]
(* {19762, {x -> 19762, y -> 7287}} *)
constraint2 /. maxX[[2]]
(* True *)
EDIT: To find maximum y
(maxY = Maximize[{y, constraint2}, {x, y}]) // N
To plot the region defined by the constraint:
reg = ImplicitRegion[constraint2, {x, y}];
Region[reg,
Frame -> True,
FrameLabel -> (Style[#, 12, Bold] & /@ {x, y}),
Epilog -> {Red,
AbsolutePointSize[3],
Point[{x, y} /. maxX[[2]]],
Point[{x, y} /. maxY[[2]]]}]
$endgroup$
add a comment |
$begingroup$
You have numbers spread a wide range of magnitudes for no good reason. This range is probably too wide for machine precision arithmetic. Also telling NMinimize
explicitly that this an integer optimization problem seems to help. Try this:
constraint2 = ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2]) || (10713. <=
x <= 19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2])) // Expand
maxX = NMaximize[{x, constraint2}, {x, y}, Integers,
MaxIterations -> 10000]
{19762., {x -> 19762, y -> 7311}}
And with your definition of constraint
:
constraint /. maxX[[2]]
True
$endgroup$
$begingroup$
Butconstraint /. x -> 19762 /. y -> 8647
results inFalse
?
$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB D'oh. Yeah, I did the simplification wrong. -.- Thanks for pointing that out.
$endgroup$
– Henrik Schumacher
11 hours ago
$begingroup$
@HenrikSchumacher, thank you for this. This works forx
but when I try to find the maximumy
similarly, I still get the same message -NMaximize[{y, res}, {x, y}, Integers, MaxIterations -> 100000]
. Output: NMaximize::cvdiv: Failed to converge to a solution. The function may be unbounded.
$endgroup$
– gaganso
11 hours ago
add a comment |
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2 Answers
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active
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2 Answers
2
active
oldest
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oldest
votes
$begingroup$
Rationalize
the constraint:
constraint2 = ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y < 2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2]) || (10713. <= x <=
19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-1 Sqrt[4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2])) //
Rationalize[#, 0] & // Simplify;
With the Rationalized
constraint you can use Maximize
:
maxX = Maximize[{x, constraint2}, {x, y}]
(* {19762, {x -> 19762, y -> 7287}} *)
constraint2 /. maxX[[2]]
(* True *)
EDIT: To find maximum y
(maxY = Maximize[{y, constraint2}, {x, y}]) // N
To plot the region defined by the constraint:
reg = ImplicitRegion[constraint2, {x, y}];
Region[reg,
Frame -> True,
FrameLabel -> (Style[#, 12, Bold] & /@ {x, y}),
Epilog -> {Red,
AbsolutePointSize[3],
Point[{x, y} /. maxX[[2]]],
Point[{x, y} /. maxY[[2]]]}]
$endgroup$
add a comment |
$begingroup$
Rationalize
the constraint:
constraint2 = ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y < 2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2]) || (10713. <= x <=
19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-1 Sqrt[4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2])) //
Rationalize[#, 0] & // Simplify;
With the Rationalized
constraint you can use Maximize
:
maxX = Maximize[{x, constraint2}, {x, y}]
(* {19762, {x -> 19762, y -> 7287}} *)
constraint2 /. maxX[[2]]
(* True *)
EDIT: To find maximum y
(maxY = Maximize[{y, constraint2}, {x, y}]) // N
To plot the region defined by the constraint:
reg = ImplicitRegion[constraint2, {x, y}];
Region[reg,
Frame -> True,
FrameLabel -> (Style[#, 12, Bold] & /@ {x, y}),
Epilog -> {Red,
AbsolutePointSize[3],
Point[{x, y} /. maxX[[2]]],
Point[{x, y} /. maxY[[2]]]}]
$endgroup$
add a comment |
$begingroup$
Rationalize
the constraint:
constraint2 = ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y < 2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2]) || (10713. <= x <=
19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-1 Sqrt[4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2])) //
Rationalize[#, 0] & // Simplify;
With the Rationalized
constraint you can use Maximize
:
maxX = Maximize[{x, constraint2}, {x, y}]
(* {19762, {x -> 19762, y -> 7287}} *)
constraint2 /. maxX[[2]]
(* True *)
EDIT: To find maximum y
(maxY = Maximize[{y, constraint2}, {x, y}]) // N
To plot the region defined by the constraint:
reg = ImplicitRegion[constraint2, {x, y}];
Region[reg,
Frame -> True,
FrameLabel -> (Style[#, 12, Bold] & /@ {x, y}),
Epilog -> {Red,
AbsolutePointSize[3],
Point[{x, y} /. maxX[[2]]],
Point[{x, y} /. maxY[[2]]]}]
$endgroup$
Rationalize
the constraint:
constraint2 = ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y < 2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2]) || (10713. <= x <=
19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-1 Sqrt[4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2])) //
Rationalize[#, 0] & // Simplify;
With the Rationalized
constraint you can use Maximize
:
maxX = Maximize[{x, constraint2}, {x, y}]
(* {19762, {x -> 19762, y -> 7287}} *)
constraint2 /. maxX[[2]]
(* True *)
EDIT: To find maximum y
(maxY = Maximize[{y, constraint2}, {x, y}]) // N
To plot the region defined by the constraint:
reg = ImplicitRegion[constraint2, {x, y}];
Region[reg,
Frame -> True,
FrameLabel -> (Style[#, 12, Bold] & /@ {x, y}),
Epilog -> {Red,
AbsolutePointSize[3],
Point[{x, y} /. maxX[[2]]],
Point[{x, y} /. maxY[[2]]]}]
edited 10 hours ago
answered 10 hours ago
Bob HanlonBob Hanlon
61.4k33598
61.4k33598
add a comment |
add a comment |
$begingroup$
You have numbers spread a wide range of magnitudes for no good reason. This range is probably too wide for machine precision arithmetic. Also telling NMinimize
explicitly that this an integer optimization problem seems to help. Try this:
constraint2 = ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2]) || (10713. <=
x <= 19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2])) // Expand
maxX = NMaximize[{x, constraint2}, {x, y}, Integers,
MaxIterations -> 10000]
{19762., {x -> 19762, y -> 7311}}
And with your definition of constraint
:
constraint /. maxX[[2]]
True
$endgroup$
$begingroup$
Butconstraint /. x -> 19762 /. y -> 8647
results inFalse
?
$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB D'oh. Yeah, I did the simplification wrong. -.- Thanks for pointing that out.
$endgroup$
– Henrik Schumacher
11 hours ago
$begingroup$
@HenrikSchumacher, thank you for this. This works forx
but when I try to find the maximumy
similarly, I still get the same message -NMaximize[{y, res}, {x, y}, Integers, MaxIterations -> 100000]
. Output: NMaximize::cvdiv: Failed to converge to a solution. The function may be unbounded.
$endgroup$
– gaganso
11 hours ago
add a comment |
$begingroup$
You have numbers spread a wide range of magnitudes for no good reason. This range is probably too wide for machine precision arithmetic. Also telling NMinimize
explicitly that this an integer optimization problem seems to help. Try this:
constraint2 = ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2]) || (10713. <=
x <= 19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2])) // Expand
maxX = NMaximize[{x, constraint2}, {x, y}, Integers,
MaxIterations -> 10000]
{19762., {x -> 19762, y -> 7311}}
And with your definition of constraint
:
constraint /. maxX[[2]]
True
$endgroup$
$begingroup$
Butconstraint /. x -> 19762 /. y -> 8647
results inFalse
?
$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB D'oh. Yeah, I did the simplification wrong. -.- Thanks for pointing that out.
$endgroup$
– Henrik Schumacher
11 hours ago
$begingroup$
@HenrikSchumacher, thank you for this. This works forx
but when I try to find the maximumy
similarly, I still get the same message -NMaximize[{y, res}, {x, y}, Integers, MaxIterations -> 100000]
. Output: NMaximize::cvdiv: Failed to converge to a solution. The function may be unbounded.
$endgroup$
– gaganso
11 hours ago
add a comment |
$begingroup$
You have numbers spread a wide range of magnitudes for no good reason. This range is probably too wide for machine precision arithmetic. Also telling NMinimize
explicitly that this an integer optimization problem seems to help. Try this:
constraint2 = ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2]) || (10713. <=
x <= 19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2])) // Expand
maxX = NMaximize[{x, constraint2}, {x, y}, Integers,
MaxIterations -> 10000]
{19762., {x -> 19762, y -> 7311}}
And with your definition of constraint
:
constraint /. maxX[[2]]
True
$endgroup$
You have numbers spread a wide range of magnitudes for no good reason. This range is probably too wide for machine precision arithmetic. Also telling NMinimize
explicitly that this an integer optimization problem seems to help. Try this:
constraint2 = ((x == 0 && 1. <= y <= 12720.) || (1. <= x <= 10712. &&
0 <= y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2]) || (10713. <=
x <= 19762. &&
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) -
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2] < y <
2.08565*10^-36 (3.04959*10^39 + 2.24751*10^34 x) +
2.8484*10^-1 Sqrt[
4.98614*10^8 + 4.65469*10^4 x - 3.63201 x^2])) // Expand
maxX = NMaximize[{x, constraint2}, {x, y}, Integers,
MaxIterations -> 10000]
{19762., {x -> 19762, y -> 7311}}
And with your definition of constraint
:
constraint /. maxX[[2]]
True
edited 11 hours ago
answered 11 hours ago
Henrik SchumacherHenrik Schumacher
59.4k582165
59.4k582165
$begingroup$
Butconstraint /. x -> 19762 /. y -> 8647
results inFalse
?
$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB D'oh. Yeah, I did the simplification wrong. -.- Thanks for pointing that out.
$endgroup$
– Henrik Schumacher
11 hours ago
$begingroup$
@HenrikSchumacher, thank you for this. This works forx
but when I try to find the maximumy
similarly, I still get the same message -NMaximize[{y, res}, {x, y}, Integers, MaxIterations -> 100000]
. Output: NMaximize::cvdiv: Failed to converge to a solution. The function may be unbounded.
$endgroup$
– gaganso
11 hours ago
add a comment |
$begingroup$
Butconstraint /. x -> 19762 /. y -> 8647
results inFalse
?
$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB D'oh. Yeah, I did the simplification wrong. -.- Thanks for pointing that out.
$endgroup$
– Henrik Schumacher
11 hours ago
$begingroup$
@HenrikSchumacher, thank you for this. This works forx
but when I try to find the maximumy
similarly, I still get the same message -NMaximize[{y, res}, {x, y}, Integers, MaxIterations -> 100000]
. Output: NMaximize::cvdiv: Failed to converge to a solution. The function may be unbounded.
$endgroup$
– gaganso
11 hours ago
$begingroup$
But
constraint /. x -> 19762 /. y -> 8647
results in False
?$endgroup$
– JimB
11 hours ago
$begingroup$
But
constraint /. x -> 19762 /. y -> 8647
results in False
?$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB D'oh. Yeah, I did the simplification wrong. -.- Thanks for pointing that out.
$endgroup$
– Henrik Schumacher
11 hours ago
$begingroup$
@JimB D'oh. Yeah, I did the simplification wrong. -.- Thanks for pointing that out.
$endgroup$
– Henrik Schumacher
11 hours ago
$begingroup$
@HenrikSchumacher, thank you for this. This works for
x
but when I try to find the maximum y
similarly, I still get the same message - NMaximize[{y, res}, {x, y}, Integers, MaxIterations -> 100000]
. Output: NMaximize::cvdiv: Failed to converge to a solution. The function may be unbounded.$endgroup$
– gaganso
11 hours ago
$begingroup$
@HenrikSchumacher, thank you for this. This works for
x
but when I try to find the maximum y
similarly, I still get the same message - NMaximize[{y, res}, {x, y}, Integers, MaxIterations -> 100000]
. Output: NMaximize::cvdiv: Failed to converge to a solution. The function may be unbounded.$endgroup$
– gaganso
11 hours ago
add a comment |
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$begingroup$
Could try maximizing over individual regions of the piecewise set-up. But the machine precision values will make validation of inequalities kind of iffy.
$endgroup$
– Daniel Lichtblau
11 hours ago
1
$begingroup$
I'm not seeing what $y$ has to do with this. Wouldn't the maximum value of $x$ be 19762?
constraint /. x -> 19762
results iny [Element] Integers && 7229.16 < y < 7344.29
andconstraint /. x -> 19763
results inFalse
.$endgroup$
– JimB
11 hours ago
$begingroup$
@JimB, I think for
x
,y
isn't needed. Thanks for pointing this out. But if I am trying to maximizey
, I need to maximize over both the variables sincey
is an expression ofx
, right?$endgroup$
– gaganso
11 hours ago
$begingroup$
Yes, if that's what you want. The general solution appears to be $x = 19762$ and $7230leq y leq 7344$. So to maximize $y$ you'd choose $7344$.
$endgroup$
– JimB
10 hours ago
1
$begingroup$
OK. I was assuming that you were conditioning on the maximum value of $x$.
$endgroup$
– JimB
10 hours ago